Fig. 4

The effects of the I423A change in different primary HIV-1 strains on Env conformational state and sensitivity to broadly neutralizing antibodies. a Neutralization of wild-type (WT) (blue) and I423A (red) HIV-1_JR-FL by different bNAbs. The calculated IC₅₀s are shown. b Conformation-selective bNAbs and sCD4 were used to test the sensitivity of the WT (blue) and the I423A variant (red) of HIV-1 strains from clades A, B, C, and D. Reported IC₅₀ units are nM for sCD4 and μg ml⁻¹ for the bNAbs. The asterisk (*) indicates that sensitivity of the PG9 antibody was tested against the HIV-1_JR-FL E168K + N188A Env (with and without the I423A change); these V2 changes restore the PG9 epitope in the HIV-1_JR-FL Env^{32, 47}. c Comparison of the sensitivity of all isolates from b to ligands that prefer State 1 and State 3. Results shown are the average of those obtained in two or three independent experiments and error bars represent s.e.m. The double asterisk (**) indicates one-tail P values <0.05